Technical Field
Embodiments of the subject matter disclosed herein relate to a turbocharged engine system including an exhaust gas recirculation system.
Discussion of Art
Engines may utilize recirculation of exhaust gas from an engine exhaust system to an engine intake system, a process referred to as exhaust gas recirculation (EGR). In some examples, a group of one or more cylinders may have an exhaust manifold that is coupled to an intake passage of the engine such that the group of cylinders is dedicated, at least under some conditions, to generating exhaust gas for EGR. Such cylinders may be referred to as “donor cylinders.” In other systems, the exhaust gas may be pulled from a manifold. Some EGR systems may include an EGR cooler to reduce a temperature of the recirculated exhaust gas before it enters the intake passage. Further, in some examples, the EGR system may route exhaust gases to an intake manifold of the intake system.
Engines may also utilize a turbocharger to provide increased power. Turbochargers function by compressing intake air in a compressor driven by a turbine operated by exhaust gas flow. In one example, the EGR system may route exhaust gases from the exhaust system, upstream of the turbine, and to the intake system, downstream of the compressor.
During engine operation, fluid (such as water or leaked coolant) may accumulate within the intake system of the engine. With the addition of the EGR system, the intake system is closed from atmosphere and there may be nowhere for accumulated fluid to go other than into the engine cylinders. However, this fluid may result in mechanical damage of engine components during engine running. Further, there may be no way to determine if coolant is leaking from the EGR cooler and accumulating within the intake manifold.